linux-stable/net/sched/act_mpls.c
Ido Schimmel bca3821d19 net/sched: act_mpls: Add extack messages for offload failure
For better error reporting to user space, add extack messages when mpls
action offload fails.

Example:

 # echo 1 > /sys/kernel/tracing/events/netlink/netlink_extack/enable

 # tc filter add dev dummy0 ingress pref 1 proto all matchall skip_sw action mpls dec_ttl
 Error: cls_matchall: Failed to setup flow action.
 We have an error talking to the kernel

 # cat /sys/kernel/tracing/trace_pipe
       tc-182     [000] b..1.    18.693915: netlink_extack: msg=act_mpls: Offload not supported when "dec_ttl" option is used
       tc-182     [000] .....    18.693921: netlink_extack: msg=cls_matchall: Failed to setup flow action

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-08 13:45:43 +01:00

495 lines
13 KiB
C

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2019 Netronome Systems, Inc. */
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mpls.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/tc_act/tc_mpls.h>
#include <net/mpls.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/tc_act/tc_mpls.h>
static unsigned int mpls_net_id;
static struct tc_action_ops act_mpls_ops;
#define ACT_MPLS_TTL_DEFAULT 255
static __be32 tcf_mpls_get_lse(struct mpls_shim_hdr *lse,
struct tcf_mpls_params *p, bool set_bos)
{
u32 new_lse = 0;
if (lse)
new_lse = be32_to_cpu(lse->label_stack_entry);
if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET) {
new_lse &= ~MPLS_LS_LABEL_MASK;
new_lse |= p->tcfm_label << MPLS_LS_LABEL_SHIFT;
}
if (p->tcfm_ttl) {
new_lse &= ~MPLS_LS_TTL_MASK;
new_lse |= p->tcfm_ttl << MPLS_LS_TTL_SHIFT;
}
if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET) {
new_lse &= ~MPLS_LS_TC_MASK;
new_lse |= p->tcfm_tc << MPLS_LS_TC_SHIFT;
}
if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET) {
new_lse &= ~MPLS_LS_S_MASK;
new_lse |= p->tcfm_bos << MPLS_LS_S_SHIFT;
} else if (set_bos) {
new_lse |= 1 << MPLS_LS_S_SHIFT;
}
return cpu_to_be32(new_lse);
}
static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_mpls *m = to_mpls(a);
struct tcf_mpls_params *p;
__be32 new_lse;
int ret, mac_len;
tcf_lastuse_update(&m->tcf_tm);
bstats_update(this_cpu_ptr(m->common.cpu_bstats), skb);
/* Ensure 'data' points at mac_header prior calling mpls manipulating
* functions.
*/
if (skb_at_tc_ingress(skb)) {
skb_push_rcsum(skb, skb->mac_len);
mac_len = skb->mac_len;
} else {
mac_len = skb_network_header(skb) - skb_mac_header(skb);
}
ret = READ_ONCE(m->tcf_action);
p = rcu_dereference_bh(m->mpls_p);
switch (p->tcfm_action) {
case TCA_MPLS_ACT_POP:
if (skb_mpls_pop(skb, p->tcfm_proto, mac_len,
skb->dev && skb->dev->type == ARPHRD_ETHER))
goto drop;
break;
case TCA_MPLS_ACT_PUSH:
new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb_protocol(skb, true)));
if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len,
skb->dev && skb->dev->type == ARPHRD_ETHER))
goto drop;
break;
case TCA_MPLS_ACT_MAC_PUSH:
if (skb_vlan_tag_present(skb)) {
if (__vlan_insert_inner_tag(skb, skb->vlan_proto,
skb_vlan_tag_get(skb),
ETH_HLEN) < 0)
goto drop;
skb->protocol = skb->vlan_proto;
__vlan_hwaccel_clear_tag(skb);
}
new_lse = tcf_mpls_get_lse(NULL, p, mac_len ||
!eth_p_mpls(skb->protocol));
if (skb_mpls_push(skb, new_lse, p->tcfm_proto, 0, false))
goto drop;
break;
case TCA_MPLS_ACT_MODIFY:
if (!pskb_may_pull(skb,
skb_network_offset(skb) + MPLS_HLEN))
goto drop;
new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
if (skb_mpls_update_lse(skb, new_lse))
goto drop;
break;
case TCA_MPLS_ACT_DEC_TTL:
if (skb_mpls_dec_ttl(skb))
goto drop;
break;
}
if (skb_at_tc_ingress(skb))
skb_pull_rcsum(skb, skb->mac_len);
return ret;
drop:
qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
return TC_ACT_SHOT;
}
static int valid_label(const struct nlattr *attr,
struct netlink_ext_ack *extack)
{
const u32 *label = nla_data(attr);
if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
return -EINVAL;
}
return 0;
}
static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
[TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
[TCA_MPLS_PROTO] = { .type = NLA_U16 },
[TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label),
[TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
[TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
[TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
};
static int tcf_mpls_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
struct tcf_proto *tp, u32 flags,
struct netlink_ext_ack *extack)
{
struct tc_action_net *tn = net_generic(net, mpls_net_id);
bool bind = flags & TCA_ACT_FLAGS_BIND;
struct nlattr *tb[TCA_MPLS_MAX + 1];
struct tcf_chain *goto_ch = NULL;
struct tcf_mpls_params *p;
struct tc_mpls *parm;
bool exists = false;
struct tcf_mpls *m;
int ret = 0, err;
u8 mpls_ttl = 0;
u32 index;
if (!nla) {
NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
return -EINVAL;
}
err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
if (err < 0)
return err;
if (!tb[TCA_MPLS_PARMS]) {
NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
return -EINVAL;
}
parm = nla_data(tb[TCA_MPLS_PARMS]);
index = parm->index;
/* Verify parameters against action type. */
switch (parm->m_action) {
case TCA_MPLS_ACT_POP:
if (!tb[TCA_MPLS_PROTO]) {
NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
return -EINVAL;
}
if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
return -EINVAL;
}
if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
tb[TCA_MPLS_BOS]) {
NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
return -EINVAL;
}
break;
case TCA_MPLS_ACT_DEC_TTL:
if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
return -EINVAL;
}
break;
case TCA_MPLS_ACT_PUSH:
case TCA_MPLS_ACT_MAC_PUSH:
if (!tb[TCA_MPLS_LABEL]) {
NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
return -EINVAL;
}
if (tb[TCA_MPLS_PROTO] &&
!eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
return -EPROTONOSUPPORT;
}
/* Push needs a TTL - if not specified, set a default value. */
if (!tb[TCA_MPLS_TTL]) {
#if IS_ENABLED(CONFIG_MPLS)
mpls_ttl = net->mpls.default_ttl ?
net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
#else
mpls_ttl = ACT_MPLS_TTL_DEFAULT;
#endif
}
break;
case TCA_MPLS_ACT_MODIFY:
if (tb[TCA_MPLS_PROTO]) {
NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
return -EINVAL;
}
break;
default:
NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
return -EINVAL;
}
err = tcf_idr_check_alloc(tn, &index, a, bind);
if (err < 0)
return err;
exists = err;
if (exists && bind)
return 0;
if (!exists) {
ret = tcf_idr_create(tn, index, est, a,
&act_mpls_ops, bind, true, flags);
if (ret) {
tcf_idr_cleanup(tn, index);
return ret;
}
ret = ACT_P_CREATED;
} else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
tcf_idr_release(*a, bind);
return -EEXIST;
}
err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
if (err < 0)
goto release_idr;
m = to_mpls(*a);
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p) {
err = -ENOMEM;
goto put_chain;
}
p->tcfm_action = parm->m_action;
p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
ACT_MPLS_LABEL_NOT_SET;
p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
ACT_MPLS_TC_NOT_SET;
p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
mpls_ttl;
p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
ACT_MPLS_BOS_NOT_SET;
p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
htons(ETH_P_MPLS_UC);
spin_lock_bh(&m->tcf_lock);
goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
spin_unlock_bh(&m->tcf_lock);
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
if (p)
kfree_rcu(p, rcu);
return ret;
put_chain:
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
release_idr:
tcf_idr_release(*a, bind);
return err;
}
static void tcf_mpls_cleanup(struct tc_action *a)
{
struct tcf_mpls *m = to_mpls(a);
struct tcf_mpls_params *p;
p = rcu_dereference_protected(m->mpls_p, 1);
if (p)
kfree_rcu(p, rcu);
}
static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_mpls *m = to_mpls(a);
struct tcf_mpls_params *p;
struct tc_mpls opt = {
.index = m->tcf_index,
.refcnt = refcount_read(&m->tcf_refcnt) - ref,
.bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
};
struct tcf_t t;
spin_lock_bh(&m->tcf_lock);
opt.action = m->tcf_action;
p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
opt.m_action = p->tcfm_action;
if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
goto nla_put_failure;
if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
goto nla_put_failure;
if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
goto nla_put_failure;
if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
goto nla_put_failure;
if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
goto nla_put_failure;
tcf_tm_dump(&t, &m->tcf_tm);
if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
goto nla_put_failure;
spin_unlock_bh(&m->tcf_lock);
return skb->len;
nla_put_failure:
spin_unlock_bh(&m->tcf_lock);
nlmsg_trim(skb, b);
return -EMSGSIZE;
}
static int tcf_mpls_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops,
struct netlink_ext_ack *extack)
{
struct tc_action_net *tn = net_generic(net, mpls_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops, extack);
}
static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, mpls_net_id);
return tcf_idr_search(tn, a, index);
}
static int tcf_mpls_offload_act_setup(struct tc_action *act, void *entry_data,
u32 *index_inc, bool bind,
struct netlink_ext_ack *extack)
{
if (bind) {
struct flow_action_entry *entry = entry_data;
switch (tcf_mpls_action(act)) {
case TCA_MPLS_ACT_PUSH:
entry->id = FLOW_ACTION_MPLS_PUSH;
entry->mpls_push.proto = tcf_mpls_proto(act);
entry->mpls_push.label = tcf_mpls_label(act);
entry->mpls_push.tc = tcf_mpls_tc(act);
entry->mpls_push.bos = tcf_mpls_bos(act);
entry->mpls_push.ttl = tcf_mpls_ttl(act);
break;
case TCA_MPLS_ACT_POP:
entry->id = FLOW_ACTION_MPLS_POP;
entry->mpls_pop.proto = tcf_mpls_proto(act);
break;
case TCA_MPLS_ACT_MODIFY:
entry->id = FLOW_ACTION_MPLS_MANGLE;
entry->mpls_mangle.label = tcf_mpls_label(act);
entry->mpls_mangle.tc = tcf_mpls_tc(act);
entry->mpls_mangle.bos = tcf_mpls_bos(act);
entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
break;
case TCA_MPLS_ACT_DEC_TTL:
NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"dec_ttl\" option is used");
return -EOPNOTSUPP;
case TCA_MPLS_ACT_MAC_PUSH:
NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"mac_push\" option is used");
return -EOPNOTSUPP;
default:
NL_SET_ERR_MSG_MOD(extack, "Unsupported MPLS mode offload");
return -EOPNOTSUPP;
}
*index_inc = 1;
} else {
struct flow_offload_action *fl_action = entry_data;
switch (tcf_mpls_action(act)) {
case TCA_MPLS_ACT_PUSH:
fl_action->id = FLOW_ACTION_MPLS_PUSH;
break;
case TCA_MPLS_ACT_POP:
fl_action->id = FLOW_ACTION_MPLS_POP;
break;
case TCA_MPLS_ACT_MODIFY:
fl_action->id = FLOW_ACTION_MPLS_MANGLE;
break;
default:
return -EOPNOTSUPP;
}
}
return 0;
}
static struct tc_action_ops act_mpls_ops = {
.kind = "mpls",
.id = TCA_ID_MPLS,
.owner = THIS_MODULE,
.act = tcf_mpls_act,
.dump = tcf_mpls_dump,
.init = tcf_mpls_init,
.cleanup = tcf_mpls_cleanup,
.walk = tcf_mpls_walker,
.lookup = tcf_mpls_search,
.offload_act_setup = tcf_mpls_offload_act_setup,
.size = sizeof(struct tcf_mpls),
};
static __net_init int mpls_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, mpls_net_id);
return tc_action_net_init(net, tn, &act_mpls_ops);
}
static void __net_exit mpls_exit_net(struct list_head *net_list)
{
tc_action_net_exit(net_list, mpls_net_id);
}
static struct pernet_operations mpls_net_ops = {
.init = mpls_init_net,
.exit_batch = mpls_exit_net,
.id = &mpls_net_id,
.size = sizeof(struct tc_action_net),
};
static int __init mpls_init_module(void)
{
return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
}
static void __exit mpls_cleanup_module(void)
{
tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
}
module_init(mpls_init_module);
module_exit(mpls_cleanup_module);
MODULE_SOFTDEP("post: mpls_gso");
MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MPLS manipulation actions");